Grammar Girl #2

1.  What I know:
 "it"  can be vague.  When people don't know what to call a fetus in the womb,  "it" is awkwardly used sometimes.

2.  Grammar Girl Episode #517 - Cut "It" Out

http://www.quickanddirtytips.com/education/grammar/do-your-readers-a-favor-cut-%E2%80%98it%E2%80%99-out

3 & 4.  http://www.huffingtonpost.com/2014/06/09/these-words-are-so-overus_n_5447356.html   Paragraph 5

Once every other song on the Top 40 station reverberates with nasal Auto-Tune, it no longer seems groundbreaking and hip, but the first artists to use it, like Cher, were thinking outside the box, finding beauty in a new and bizarre tool. 

The first "it" in the paragraph could be confusing, because someone could try to refer "it" back to either the Top 40 station or the nasal Auto-Tune.  By the second "it" I became more aware that the author is referring to the Auto-Tune because he writes that artists use "it".  I'm not saying that clarification is absolutely needed, but the author could have been more specific if he wanted to.

...reverberates with nasal Auto-Tune, the sound no longer seems groundbreaking..

What I learned:  It" is used in a lot of places where a different word could go, to clarify what you are referring to.  The writer could keep the reader focused more if the word "it" is cut out of the sentence when it's simple to define what "it" is.